GRATES

**Definition:** This place covers:

All details of combustion grates, including all relevant accessories and peripheral devices such as driving mechanisms or cooling arrangements for example, independently from the type of solid fuel which is supported and burned on the grate.

**Limiting references (this place does not cover):** - Inlets for fluidisation air for fluidised bed combustion apparatus -> F23C10/20

**Glossary:** - Air: a mixture of gases containing free oxygen and able to promote or support combustion - Primary air: air supplied to the burning fuel in order to liberate combustible gases - Secondary air: air supplied to the combustible gases liberated by the primary air in order to complete their combustion. The term "secondary air" covers "tertiary air" etc. - Ash: means any solid combustion residues, for example remaining in the fuel bed or suspended in the flue gases - Burner: a device by which fluid fuel or solid fuel suspended in air is passed to a combustion space where it burns to produce a self-supporting flame - Combustion: means the direct combination of oxygen gas, e.g. in air and a burnable substance - Combustion chamber: a chamber in which fuel is burned to establish a self-supporting fire or flame and which surrounds that fire or flame - Combustion zone: the part of the apparatus where the reaction takes place between air and fuel - Flue gases: any gaseous products of combustion - Grate: a perforated surface, e.g. a grid which supports or delimits a bed of burning fuel and serves to supply primary air